Apparatus for manufacturing inked ribbons



June 4, 1940. F. A. WALDRON APPARATUS FOR MANUFACTURING INKED RIBBONSOriginal Filed July 19, 1952 m r M w w mA .m e M f F BY jg M W ATTORNEYPatented June 4, 1940 U Q I r UNITED STATES PATENT 'OFFiCE APPARATUS FORMANUFACTURING INKEi) RIBBONS Frederick A. Waldron, Westfield, J.

Original application July 19, 1932, Serial No.

623,368. Divided and this application November 19, 1938, Serial No.241,311

6 Claims. (01. 91--55) The present invention relates to apparatus forresume their original form with a thinner film of the manufacturing ofinked ribbons such as used ink between them. This juicy conditioncontinin typewriters, computing machines, multigraphues until the freeink has been removed by ing machines and the like. splashing it out ofthe ribbon.

: These ribbons are made out of finely woven The present inventioncontemplates improve- 5 fabric, such as muslin, cotton, or silk, andaccordments in the manufacture of typewriter ribbons ing to the methodscommonly employed, a strip of and the like whereby the pigment oil ratioin the this material is, without any preliminary treatfinished ribbon ispredetermined "and materially ment, passed through an ink bath (composedof greater than in the original ink bath, so that the 10 suitablepigment in an oil base) so that capillary ribbon may have a longer lifeand be of more 10 attraction will cause an absorption of ink. It uniformshade during use. At the samev time exis then subjected to pressurerolls to regulate the cessive juiciness of the new ribbon is avoided andinking of the ribbon. A light roll pressure proinitial outward flow ofink to paper retarded and duces a heavily inked, more juicy ribbon whichheld back for more efficient future use. Further- 18. gives wet anddarkly shaded, dense printing, more the recovery of the ribbon after arest is and more or less splashjwhile with heavier roll improved.pressure the ribbon retains less ink so that the Accordingly, the ribbonis, during the process ribbon is less juicy and the printing is of alighter of manufacture, subjected to a process wherein shade. With thesame ink bath, the shade variathe impregnation is accomplished in avacuum tion is obtained by variation of roll pressure. treated strip offabric without mechanically 0 The rolling orsqueezing of the ribbonwet/with squeezing the strip or'iiattening out the fibres. ink is not aselective operation, for coloring mat- This impregnated strip willabsorb more pigment ter and oil are pressed out in substantially the andvehicle than where the former squeezing same proportion in which theywere present in process is relied upon. To retain the added pig- "theink bath. There is, therefore, less actual pigment, the inventioncontemplates expanding or 25 ment in the ribbon subjected to the greaterpresexploding the threads of fabric and reducing air sure and hence itsuseful life ismuch impaired. space and the removal by evaporation underre- In the manufacture of ribbons, no attention duced pressure and atlow heat of the excessveseems to have been given to the hygroscopichicle (or 'oil) only, in order that the finished property of thefabric,whereby more or less moisproduct shall contain a maximum amount of inkture is absorbed from the atmosphere. This of a predeterminedcontrollable content of oil moisture variation varies the condition ofthe and pigment whereby the pigment. is not-injured. fibres (as is wellknown in the textile art) and its According to the present invention,the mapresence resists theabsorption of the oil and terial is passedrapidly from the atmosphere 5 pigment. This brings about a lack ofuniformity through a liquid seal (preferably mercury) and of thefinished product. communicating with a high vacuum chamber, so'I'hefabric used for ribbon manufacture apthat moisture, air, and gases(principally water pears to the naked eye to be closely woven, butvapor) may be removed from the strip. The eswhen held up to the light,or when observed uncape ofthe air and gases is so sudden that the 40 dera low power microscope, it has the appearfibres are loosened andexpanded, and hence the ance of afairly open screen. Whenthis fabricthread size is increased." The vacuum chamber is immersed into the inkbath, the ink penetrates s asso with One Side Of a q Seal hav. thefibres and fills the interstices between the ng at and p t ng bath ofink, prefthreads. The pressure applied by the rolls not erably floatedon mercury. The surface of th ,5 only squeezes out the pigment and oilbut also liquid in S6941 y bev eXposed t0 the atmosacts to flatten outthe threads and reduce the p e So as to p t e Sucking up of theliqintersticial areas. Release of the pressure allows uid. In thismanner the strip material isP d the threads to resume their originalform so as direc ly o the Vacuum into the inkbath withto absorb more orless of the ink film extending out affording any opportunity for theabsorption across the interstices. There is, however, 0011- of air orgasesbs the vacuum treated material. siderable free ink in this filmcausing juiciness. It is carried through the coating liquid di- When theribbon is struck by the type, the threads. rectly into mercury so as tobe subjected to a are flattened out, the intersticial spaces reduced,pressure difference depending upon the amount and this free ink splashesout onto the paper and of vacuum and the depth of immersion below thetype. On release of the pressure, the threads exposed surface of thecoating or impregnating liquid or mercury. The liquid pressure acts toforce the ink into the evacuated strip and does not mechanically squeezeit out, as do the pressure rollers.

The strip material then passes upwardly through the liquid seal and intothe same or a second vacuum chamber where it is heat treated undervacuum. For typewriter ribbon manufacture, this operation is carried outso that the temperature of the ribbon is kept below that injurious toink or pigment, but above the vaporization point of the oil vehicle.This temperature will vary in range depending on the characteristics ofmaterials used and final oil content required, but will in no eventimpair or injure the pigment of the ink, but will be sufiicient tovaporize and promote rapid evaporation of the oil to the requiredamount. The strip now contains all the pigment which it had absorbed,but less oil. It is then preferably subjected to a squeezing operationwhile still under the vacuum, so that the pigment is compacted, andkneaded into the fabric, and a suitable, smooth finish provided. Thematerial is then passed through another mercury seal to compensate forthe pressure difference between this second chamber and the atmosphere.

The accompanying drawing shows, for purposes of illustrating the presentinvention, one of the many embodiments in which the invention may takeform, it being understood that the drawing is illustrative of theinvention rather than limiting the same.

In this drawing:

Figure 1 is a diagrammatic sectional view through an apparatus suitablefor the manufacture of typewriter ribbons;

Figures 2 and 3 are fragmentary sectional views on the lines 2-2 and 3-3of Figure 1;

Figures 4 and 5 are diagrammatic views illustrating the normal threadsize and the enlarged thread size caused by sudden evacuation ofmoisture and gases from the fabric; and

Figures 6 and 7 illustrate the condition in former ribbons overcome inribbon made as described herein.

The apparatus comprises two stationary vacuum compartments A and Bcarrying downwardly extending suction tubes as indicated at I0, II, I2,and I3, and guides in the form of rollers M and I6, or glass rods I5,I5, I5". These guides are immersed in containers or pets II, I8, and I9.These containers may be carried on some form of jack, such for exampleas a hydraulic jack, as indicated at I9 or 2|, or they may be carried ona suspension, such as shown at 29.

When the containers are in the upper position, they receive the guidesand when lowered they are a substantial distance below the guides tofacilitate threading the strip through the apparatus. Each of thesecontainers is adapted to contain an inert liquid, such as mercury, intowhich the lower ends of the tubes I0, H, I2, and I3 extend. The chambersA and B are connected to a suitable exhaust pump, indicated at 22, so asto evacuate the air and gases from the chambers, and when the air isevacuated from these chambers, the mercury is sucked up into the tubesIn, II, I2, and I3 as indicated. The twocompartment arrangement ispreferred over a larger single vacuum chamber, as it permits a moreflexible control.

A supply of ribbon fabric R is indicated at 25. It is fed downunderneath the roller I4 up through the suction tube I I), and intovacuum chamber A where it passes between two electric heaters 26, 26pressed toward one another by springs 21 so as to heat the fabric,preferably without ironing it.

The compartment A contains two guide rollers 28 and 29, one above thesuction tube II], the other above the suction tube II.

An ink reservoir is indicated at 30. It is connected by float valve 3|and pipe 32 so as to discharge ink into the lower part 33 of the chamberA where it floats on top of the mercury in column I I.

I'he ribbon R passes down through the ink bath between scrapersindicated at 34 and into the mercury tube II. It then passes underneathbetween the glass guides or rolls I5, I5, and I5 which exert somescraping action, and continues up through the mercury column I2. It thenpasses by scrapers indicated at 35 and 36 and between electric or otherheaters 31, 31. These heaters may be suspended from the point 38, ifdesired. The ribbon then passes about a roller 39 (which may, ifdesired, be heated) and between this roller and a second or pressureroller The meeting line of these rollers is directly above suction tubeI 3. If desired, the ribbon may be passed between heaters 4|, 4| beforeentering the mercury in the tube I3. -It then passes down underneath theroller I6 and up into a winding reel M. The rollers 39 and 4B are powerdriven and are pressed toward one another by an adjustable weight 43carried on a bell crank arm M which pushes the roller 40 against theroller 39. The reel 42 is driven by 'a'suitable reeling mechanism.

The strip of fabric R is drawn through the apparatus at a comparativelyhigh speed in the direction indicated by the arrows. The fabric on theroller 25 is the ordinary fabric employed for typewriter ribbons. Itcontains air, moisture, and gases, and is drawn underneath the mercuryin container I! and up through the tube II. It suddenly emerges into thevacuum chamber and immediately passes through the heating zone caused bythe heaters 26, 26. This operation brings about a sudden release of theair and gases, particularly moisture vapor, from the fibres, and causesthe fibres to-swell, expand materially as indicated diagrammatically inthe differences be tween Figures 4 and 5. The rapid escape of the airand gases from the inside of the fibres looses and expands the fibresand closes up the interstices between the threads.

While the fabric is in this condition, it is high- I 1y absorbent. It isplunged underneath the ink in the ink bath and carried directly downinto the mercury tube II under and underneath the guides.

Owing to the great difference in the specific gravity of the ink andmercury the mercury acts as a frictionless distributor of ink throughoutthe fabric. This method of ink distribution in the fabric is also usefulin processes wherein there is no preliminary evacuation .of air andgases. As the coated fabric becomes more submerged in the mercurycolumn, the ink absorbed by the evacuated fibres is pressed into thefibres by liquid pressure above atmospheric. true impregnation of thefabric for the fabric with fresh ink is subjected to the pressure aboveatmospheric while the ink is still in theliquid state without any dryingor evaporating of the This effects a vehicle. True impregnation cannotbe accom- 75 plished' in a vacuum alone. In the present case the mercurycolumn acts as a hydrostatic impregnator producing a continuous effectnormally obtained by pressure pumps on the intermittent impregnatingprocesses. It alsoacts'as a seal. A pressure diiferenoe, somewhat morethan fifteen pounds per square inch, is available for pressing the inkinto the fibres without any rolling or squeezing action which would tendto distort the fibres or remove the ink from the fibres. The mercuryitself effects a fixed and uniformly distributed quantity of ink in thefabric. The ribbon then passes between the scrap ers 35 and 36, whichare adjustable by means of the linkage indicated, so as to removemechanically carried excess of ink.

The ribbon then passes between the heaters 31, 31 which effect a heattreatment on the ribbon. The temperature of these heaters and the speedof motion of the ribbon, is so adjusted that a very substantial portionof the volatile matter of the ink, principally oil, is evaporated at thereduced pressure, thereby decreasing the amount of oil carried in theribbon without decreasing the amount of pigment carried by the ribbon.This temperature is so low as not to eflect the pigment hence the colorand other inking properties are not injured.

This operation effects an increase in the pig men's-vehicle ratio sothat the ribbon passing between the pressure rollers 39, 4 carries thefull quota of pigment but much less oil or vehicle than would be thecase were the ribbon subjected to the usual pressure rolling. Thepressure rolling operation acts to further press the pigment into thefibres and to give a smooth finish to the ribbon. The ribbon is thenpassed through. the inert mercury column in tube i3 and. under roller itto the winding mechanism.

Owing to the speed at which the ribbon is passed through the apparatus,there is some tendency of the mercury to be bodily displaced by theribbon, or to surge on account of'its movement. To cut down the movementof the mercury, one may insert an open coiled spring in each tube, asindicated at 45. Drain cocks 45 and 41 may be provided for draining offthe ink or scrapings, and additional scrapers 41, Ml may be provided forthe rollers 39 and 4!].

Figures 6 and '7 illustrate the conditions'present in ribbons of theprior art. are partially filled with ink and the free ink fills theinterstices as shown at I, Figure 6. When a type character 0 strikes theribbon, it flattens out the threads and closes the interstices somewhatas shown in Figure 7. The free ink splashes out onto the type and papermaking a ragged impression. On release of the pressure, the threadsresume their former shape but less ink is in the interstices, asindicated by the dotted lines in Figure 6.

Ribbons made according to this process are characterized by a markedincrease in opacity when held up to the light. They have a much greaterpigment-vehicle ratio than is possible in the usual process of rollingwhich merely removes oil and pigment in the same proportions as in theink bath. Thiseffects a material and controlled increase in theviscosity and flowing power of the ink in the finished ribbon. There isno free ink to splash out and the juiciness of the new ribbon ismaterially reduced. This materially prolongs the life of the ribbon. Theprocess furthermore provides a very Well filled storage reservoir in themargins of the ribbon v changing the pressure.

. b7 and inthe center of the ribbon (not'struck by the type) so that therecovery of the ribbon after a rest period is far greater than that normally experienced with ordinary ribbons. Uniform, clear, sharpimpressions are produced un-' til the fabric is destroyed. 7

The shade of the written matter may be controlled by changing th inkused ratherthan by Shade of writing is; therefore, not solely dependenton the amount of pigment carried by the ribbon but depends rather uponthe color of the pigment used.

The present application is a division of my co-pending applicationSerial No. 623,368, filed July 19, 1932.

It is obvious that the invention may be embodied in many forms andconstructions, and I wish it to be understood that the particular formshown is but one of the many forms. Various modifications and changesbeing possible, I do not otherwise limit myself in any way with respectthereto.

What is claimed is:

'1. Apparatus for continuously manufacturing typewriter ribbons, and thelike, from a strip of fabric, comprising a two-compartment vacuumchamber, a liquid inlet seal having a suction tube connected to onecompartment, a liquid outlet seal having a suction tube connected to theother compartment, a dual seal having two suction tubes, one connectedto each. compartment, each including a liquid container and a guide, thecontainers being open to' the atmosphere and containing an inertliquidadapted to be sucked up into the tubular connections, an ink bathfloated on top of the liquid in the tube leading from the firstcompartment to the dual seal, and guides in the compartments, all theguides being arranged for the continuous movement of the strip fro s.the atmosphere through the seals and compartments and to return it tothe atmosphere.

v2. Apparatus for continuously manufacturing typewriter ribbons, and thelike, from a strip of fabric, comprising a two-cornpartment vacuumchamber, a heater in each compartment, a liquid inlet seal havingsuction tube connected to one compartment, a liquid outlet seal having asuction tube connected to the other compartment, a dual seal having twosuction tubes, one connected to each compartment, each seal including aliquid container and a guide, the containers being open to theatmosphere and containing an inert liquid adapted to be sucked up intothe tubular connections, an ink bath floated on top of the liquid in thetube leading from the first compartment to the dual seal, and guides inthe compartments, all the guides being arranged for the continuousmovement of the strip from the at mosphere through the seals, heaters,and compartrnents and to return it to the atmosphere.

3. Apparatus as defined in claim .1, having means for heating the stripas it passes through the vacuum compartments, and pressure rolls in thesecond chamber through which the heat treated strip passes.

4. Apparatus as defined in claim 1, having ink removing devices in thesecond compartment and acting on the fabric strip after it emerges fromthe second seal, a heater in the second compartment for removing aportion of the vehicle from the fabric, and pressure rollers forpressing the pigment into the fabric.

5. Apparatus for manufacturing typewriter ribbons'and the like,comprising an ink'bath, a liquid container open to the atmosphere, aninert liquid therein, a guide in the liquid container, tubes extendingupwardly from the liquid container and opening below the surface of theliquid, vacuum chambers into which the upper ends of said tubes open,and guide rollers in each chamber, liquid seals between the atmosphereand each chamber, each seal having a guide immersed in the liquidtherein, all said guides being below the exposed surfaces of the liquidseals and disposed m to guide a ribbon through the seals, chambers,

and tubes, and to subject the ribbon to pressures above atmospheric ineach seal, the ink bath being disposed in the path of the ribbon andintermediate the inert liquid and the first chamber.

6. Apparatus as set forth in claim 5, characterized in that each of thethree seals is a mercury seal and in that the ink floats on top of themercury in the admission side of the first mentioned seal.

FREDERICK A. WALDRON.

